Leaked source code of windows server 2003
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262 lines
6.6 KiB

/*
* MAPI 1.0 property handling routines
*
* RK.C -
*
* Two Rabin/Karp string finding functions
* The two are almost identical.
*/
#include "_apipch.h"
#define ulPrime ((ULONG) 0x00FF00F1)
#define ulBase ((ULONG) 0x00000100)
BOOL FRKFindSubpb(LPBYTE pbTarget, ULONG cbTarget,
LPBYTE pbPattern, ULONG cbPattern)
{
UINT i;
LPBYTE pbTargetMax = pbTarget + cbTarget;
LPBYTE pbPatternMax = pbPattern + cbPattern;
ULONG ulBaseToPowerMod = 1;
ULONG ulHashPattern = 0;
ULONG ulHashTarget = 0;
if (cbPattern > cbTarget)
return FALSE;
// Compute the power of the left most character in base ulBase
for (i = 1; i < cbPattern; i++)
ulBaseToPowerMod = (ulBase * ulBaseToPowerMod) % ulPrime;
// Calculate the hash function for the src (and the first dst)
while (pbPattern < pbPatternMax)
{
ulHashPattern = (ulHashPattern*ulBase+*pbPattern) % ulPrime;
ulHashTarget = (ulHashTarget*ulBase+*pbTarget) % ulPrime;
pbPattern++;
pbTarget++;
}
// Dynamically produce hash values for the string as we go
for ( ;; )
{
// Remember to do the memcmp for the off-chance it doesn't work
// according to probability
if ( ulHashPattern == ulHashTarget
&& !memcmp(pbPattern-cbPattern, pbTarget-cbPattern,
(UINT)cbPattern))
return TRUE;
// Assert because this is very unprobable
#ifdef DEBUG
if (ulHashPattern == ulHashTarget)
DebugTrace( TEXT("This is very unprobable!\n"));
#endif
if (pbTarget == pbTargetMax)
return FALSE;
ulHashTarget = (ulHashTarget+ulBase*ulPrime-
*(pbTarget-cbPattern)*ulBaseToPowerMod) % ulPrime;
ulHashTarget = (ulHashTarget*ulBase+*pbTarget) % ulPrime;
pbTarget++;
}
}
// Note - 4/14/97
// Replaced FGLeadByte() with IsDBCSLeadByte()
LPSTR LpszRKFindSubpsz(LPSTR pszTarget, ULONG cbTarget, LPSTR pszPattern,
ULONG cbPattern, ULONG ulFuzzyLevel)
{
#ifdef OLDSTUFF_DBCS
LCID lcid = GetUserDefaultLCID();
LANGID langID = LANGIDFROMLCID(lcid);
LPBYTE pbTarget;
LPBYTE pbPattern;
BOOL fResult = FALSE;
ULONG ulchPattern; // cbPattern in character unit.
ULONG ulcbTarget = cbTarget;
ULONG ulcbEndTarget; // = cbPattern at the end of pszTarget
const ULONG ulCharType = UlGCharType(pszPattern);
pbTarget = (LPBYTE) pszTarget;
pbPattern = (LPBYTE) pszPattern;
ulchPattern = ulchStrCount(pbPattern, cbPattern, langID);
ulcbEndTarget = ulcbEndCount(pbTarget, cbTarget, ulchPattern, langID);
if (ulcbEndTarget == 0)
goto end;
while(ulcbEndTarget <= ulcbTarget)
{
const BOOL fTargetDBCS = IsDBCSLeadByte(*pbTarget);
BOOL fCompare = TRUE;
if (!fTargetDBCS)
{
if (ulCharType & (CK_ALPHABET | CK_NUMERIC))
{
if (!IsCharAlphaNumeric(*pbTarget))
fCompare = FALSE;
}
else
{
if (IsCharAlphaNumeric(*pbTarget))
fCompare = FALSE;
}
}
if (fCompare && CompareStringA(lcid,
((ulFuzzyLevel & FL_IGNORECASE) ? NORM_IGNORECASE | NORM_IGNOREKANATYPE | NORM_IGNOREWIDTH : 0) |
((ulFuzzyLevel & FL_LOOSE) ? NORM_IGNORECASE | NORM_IGNOREKANATYPE | NORM_IGNOREWIDTH : 0) |
((ulFuzzyLevel & FL_IGNORENONSPACE) ? NORM_IGNORENONSPACE : 0),
pbPattern,
cbPattern,
pbTarget,
ulcbStrCount(pbTarget, ulchPattern, langID)) == 2 )
{
fResult = TRUE;
goto end;
}
// pszTarget may contain the hi-ansi characters. fTargetDBCS may
// not be true.
if (fTargetDBCS && ulcbTarget > 1)
{
ulcbTarget -= 2;
pbTarget += 2;
}
else
{
ulcbTarget --;
pbTarget ++;
}
}
#else
UINT i;
ULONG ulBaseToPowerMod = 1;
ULONG ulHashPattern = 0;
ULONG ulHashTarget = 0;
LCID lcid = GetUserDefaultLCID();
LPBYTE pbTarget;
LPBYTE pbPattern;
LPBYTE pbTargetMax;
LPBYTE pbPatternMax;
BOOL fResult = FALSE;
CHAR *rgchHash;
// Validate parameters
switch (ulFuzzyLevel & (FL_IGNORECASE | FL_IGNORENONSPACE))
{
default: case 0:
rgchHash = (CHAR*)rgchCsds;
break;
case FL_IGNORECASE:
rgchHash = (CHAR*)rgchCids;
break;
case FL_IGNORENONSPACE:
rgchHash = (CHAR*)rgchCsdi;
break;
case FL_IGNORECASE | FL_IGNORENONSPACE:
rgchHash = (CHAR*)rgchCidi;
break;
}
// Special case for single character pattern strings
if (cbPattern == 1 && cbTarget >= 1) {
BYTE chPattern = (BYTE)*pszPattern;
pbTarget = (LPBYTE)pszTarget;
while (*pbTarget && *pbTarget != chPattern) {
pbTarget++;
}
if (*pbTarget == chPattern) {
return(pbTarget);
} else {
return(NULL); // not found
}
}
//$ Is this what we want FL_LOOSE to mean?
if (ulFuzzyLevel & FL_LOOSE)
rgchHash = (CHAR*)rgchCids;
pbTarget = (LPBYTE) pszTarget;
pbPattern = (LPBYTE) pszPattern;
pbTargetMax = pbTarget + cbTarget;
pbPatternMax = pbPattern + cbPattern;
if (cbPattern > cbTarget)
goto end;
// Compute the power of the left most character in base ulBase
for (i = 1; i < cbPattern; i++)
ulBaseToPowerMod = (ulBase * ulBaseToPowerMod) % ulPrime;
// Calculate the hash function for the src (and the first dst)
while (pbPattern < pbPatternMax)
{
ulHashPattern = (ulHashPattern*ulBase+rgchHash[*pbPattern]) % ulPrime;
ulHashTarget = (ulHashTarget*ulBase+rgchHash[*pbTarget]) % ulPrime;
pbPattern++;
pbTarget++;
}
// Dynamically produce hash values for the string as we go
for ( ;; )
{
if (ulHashPattern == ulHashTarget)
{
if (CompareStringA(lcid,
((ulFuzzyLevel & FL_IGNORECASE) ? NORM_IGNORECASE : 0) |
((ulFuzzyLevel & FL_LOOSE) ? NORM_IGNORECASE : 0) |
((ulFuzzyLevel & FL_IGNORENONSPACE) ? NORM_IGNORENONSPACE : 0),
pbPattern-cbPattern, (UINT)cbPattern,
pbTarget-cbPattern, (UINT)cbPattern) == 2)
{
fResult = TRUE;
pbTarget -= cbPattern;
goto end;
}
}
#ifdef DEBUG
if (ulHashPattern == ulHashTarget)
DebugTrace( TEXT("This is very unprobable, unless you are doing ")
TEXT("FL_EXACT and an case insensitive match came up ")
TEXT("(or you are on DBCS)\n"));
#endif
if (pbTarget == pbTargetMax)
goto end;
ulHashTarget = (ulHashTarget+ulBase*ulPrime-
rgchHash[*(pbTarget-cbPattern)]*ulBaseToPowerMod) % ulPrime;
ulHashTarget = (ulHashTarget*ulBase+rgchHash[*pbTarget]) % ulPrime;
pbTarget++;
}
#endif
end:
return fResult ? pbTarget : NULL;
}
BOOL FRKFindSubpsz(LPSTR pszTarget, ULONG cbTarget, LPSTR pszPattern,
ULONG cbPattern, ULONG ulFuzzyLevel)
{
return !!LpszRKFindSubpsz (pszTarget,
cbTarget,
pszPattern,
cbPattern,
ulFuzzyLevel);
}